The last remaining nuclear arms pact between Russia and the United States is set to expire Thursday, removing any caps on the two largest atomic arsenals for the first time in more than half a century. The termination of the New START Treaty would mark a significant turning point in nuclear arms control, potentially setting the stage for an unconstrained nuclear arms race between global superpowers.
Russian President Vladimir Putin has declared readiness to stick to the treaty’s limits for another year if Washington follows suit, but President Donald Trump has remained noncommittal about extending the agreement. According to a White House official speaking on condition of anonymity, Trump has repeatedly indicated interest in keeping limits on nuclear weapons and involving China in arms control talks, though he will make a decision “on his own timeline.”
Understanding the New START Treaty Expiration
New START, signed in 2010 by U.S. President Barack Obama and Russian President Dmitry Medvedev, restricted each side to no more than 1,550 nuclear warheads on no more than 700 missiles and bombers. The pact was originally supposed to expire in 2021 but was extended for five more years. It envisioned sweeping on-site inspections to verify compliance, although they stopped in 2020 because of the COVID-19 pandemic and never resumed.
In February 2023, Putin suspended Moscow’s participation, saying Russia couldn’t allow U.S. inspections of its nuclear sites while Washington and NATO allies openly declared Moscow’s defeat in Ukraine as their goal. However, the Kremlin emphasized it wasn’t withdrawing from the nuclear arms pact altogether, pledging to respect its caps on nuclear weapons.
Global Concerns Over Arms Race
Arms control advocates have voiced serious concern about the expiration of New START, warning it could lead to a new Russia-U.S. arms race and increase the risk of nuclear conflict. Kremlin spokesman Dmitry Peskov said Tuesday it would be a “more dangerous” world without limits on U.S. and Russian nuclear stockpiles. Additionally, Pope Leo XIV called Wednesday for the treaty “not to be abandoned without seeking to ensure its concrete and effective continuation.”
Daryl Kimball, executive director of the Arms Control Association in Washington, warned that failure to agree on keeping the pact’s limits will likely encourage bigger deployments. According to Kimball, the expiration could open up the possibility of “an unconstrained, dangerous three-way arms race, not just between the U.S. and Russia, but also involving China, which is also increasing its smaller but still deadly nuclear arsenal.”
Historical Context of Nuclear Treaties
New START followed a long succession of U.S.-Russian nuclear arms reduction pacts, starting with SALT I in 1972 signed by U.S. President Richard Nixon and Soviet leader Leonid Brezhnev. The 1972 Anti-Ballistic Missile Treaty restricted missile defense systems until President George W. Bush withdrew the U.S. from the pact in 2001 despite Moscow’s warnings.
Meanwhile, the Intermediate-range Nuclear Forces Treaty, signed in 1987, was terminated in 2019. That agreement had banned land-based missiles with ranges between 500-5,500 kilometers, which were considered particularly destabilizing due to their short flight time.
Implications for Strategic Stability
Kingston Reif of the RAND Corporation, a former U.S. deputy assistant secretary of defense, warned that “in the absence of the predictability of the treaty, each side could be incentivized to plan for the worst or to increase their deployed arsenals to show toughness and resolve.” Putin has repeatedly brandished Russia’s nuclear might since sending troops into Ukraine in February 2022, warning Moscow was prepared to use “all means” to protect its security interests.
In contrast to previous diplomatic approaches, Trump’s proposed Golden Dome missile defense system has worried Russia and China, according to Kimball. He noted they’re likely to respond by building up offensive weapons to overwhelm the system. Furthermore, Trump’s October statement about U.S. intentions to resume nuclear tests for the first time since 1992 has troubled the Kremlin, with Putin saying Russia will respond in kind if the U.S. resumes tests.
Authorities have not confirmed specific plans for negotiations beyond Thursday’s deadline. The uncertainty surrounding the treaty’s future leaves open the possibility that the world could enter what Kimball described as “a much more dangerous period of global nuclear competition, the likes of which we’ve not seen in our lifetimes.”





